U.S. patent number 10,510,639 [Application Number 15/749,543] was granted by the patent office on 2019-12-17 for vehicle control device.
This patent grant is currently assigned to AISIN AW CO., LTD.. The grantee listed for this patent is AISIN AW CO., LTD.. Invention is credited to Riku Kambe, Yusuke Yamamoto.
United States Patent |
10,510,639 |
Yamamoto , et al. |
December 17, 2019 |
Vehicle control device
Abstract
A vehicle control device (100) includes: a housing (200) made of
metal; a substrate (400) housed in the housing (200) and having a
mounting surface (401) that faces an inner surface (201) of the
housing (200); and an electronic component (501) mounted on the
mounting surface (401). An adhesive (601) is disposed between the
electronic component (501) and the inner surface (201) of the
housing (200). The electronic component (501) has a contact portion
(532) that contacts the heat radiation material (601) and a
non-contact portion (531) that does not contact the heat radiation
material (601). The contact portion (532) and the non-contact
portion (531) are portions of the electronic component (501) on the
side facing the inner surface (201) of the housing (200).
Inventors: |
Yamamoto; Yusuke (Okazaki,
JP), Kambe; Riku (Nagoya, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
AISIN AW CO., LTD. |
Anjo-shi, Aichi-ken |
N/A |
JP |
|
|
Assignee: |
AISIN AW CO., LTD. (Anjo-shi,
Aichi-ken, JP)
|
Family
ID: |
58386095 |
Appl.
No.: |
15/749,543 |
Filed: |
September 26, 2016 |
PCT
Filed: |
September 26, 2016 |
PCT No.: |
PCT/JP2016/078260 |
371(c)(1),(2),(4) Date: |
February 01, 2018 |
PCT
Pub. No.: |
WO2017/051925 |
PCT
Pub. Date: |
March 30, 2017 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20180226319 A1 |
Aug 9, 2018 |
|
Foreign Application Priority Data
|
|
|
|
|
Sep 24, 2015 [JP] |
|
|
2015-186640 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L
23/3737 (20130101); H01L 23/42 (20130101); H01L
23/49513 (20130101); H01L 23/3675 (20130101); H05K
7/1427 (20130101); H05K 1/0209 (20130101); B60R
16/02 (20130101); H05K 9/0009 (20130101); H01L
23/373 (20130101); H01L 24/48 (20130101); H01L
2224/45099 (20130101); H01L 2224/32245 (20130101); H01L
2224/73265 (20130101); H01L 2924/13091 (20130101); H01L
2224/48091 (20130101); H01L 2924/181 (20130101); H01L
2224/48247 (20130101); H01L 2224/48091 (20130101); H01L
2924/00014 (20130101); H01L 2924/181 (20130101); H01L
2924/00012 (20130101); H01L 2224/73265 (20130101); H01L
2224/32245 (20130101); H01L 2224/48247 (20130101); H01L
2924/00 (20130101); H01L 2224/73265 (20130101); H01L
2224/32245 (20130101); H01L 2224/48247 (20130101); H01L
2924/00012 (20130101); H01L 2924/13091 (20130101); H01L
2924/00 (20130101); H01L 2224/45099 (20130101); H01L
2924/00014 (20130101) |
Current International
Class: |
H05K
7/14 (20060101); H01L 23/495 (20060101); H01L
23/373 (20060101); H01L 23/00 (20060101); H05K
1/02 (20060101); H05K 9/00 (20060101); B60R
16/02 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
09-298889 |
|
Nov 1997 |
|
JP |
|
2002-167560 |
|
Jun 2002 |
|
JP |
|
2002-185183 |
|
Jun 2002 |
|
JP |
|
2002167560 |
|
Jun 2002 |
|
JP |
|
2004-228162 |
|
Aug 2004 |
|
JP |
|
2007-005390 |
|
Jan 2007 |
|
JP |
|
2011-192937 |
|
Sep 2011 |
|
JP |
|
2011192937 |
|
Sep 2011 |
|
JP |
|
2011-258882 |
|
Dec 2011 |
|
JP |
|
2012-146778 |
|
Aug 2012 |
|
JP |
|
2012146778 |
|
Aug 2012 |
|
JP |
|
Other References
International Search Report of PCT/JP2016/078260 dated Dec. 6,
2016. cited by applicant.
|
Primary Examiner: Nguyen; Hoa C
Assistant Examiner: DePew; Keith
Attorney, Agent or Firm: Sughrue Mion, PLLC
Claims
The invention claimed is:
1. A vehicle control device comprising: a housing mounted on a
vehicle and made of metal; a substrate housed in the housing and
having a mounting surface that faces an inner surface of the
housing; an electronic component mounted on the mounting surface;
and a heat radiation material disposed between the electronic
component and the inner surface of the housing, wherein the
electronic component has a contact portion that contacts the heat
radiation material and a non-contact portion that does not contact
the heat radiation material, the contact portion and the
non-contact portion being portions of the electronic component on a
side facing the inner surface of the housing: the electronic
component has a first circuit portion and a second circuit portion;
the first circuit portion radiates a larger amount of noise than an
amount of noise radiated from the second circuit portion, and is
superposed on the non-contact portion as seen in a direction that
is perpendicular to the mounting surface; and a distance between
the non-contact portion and the inner surface of the housing in a
direction that is perpendicular to the mounting surface is longer
than a distance between the contact portion and the inner surface
of the housing in the perpendicular direction.
2. The vehicle control device according to claim 1, wherein the
inner surface of the housing has a recessed portion disposed at a
position facing the non-contact portion and recessed in a direction
away from the electronic component.
3. The vehicle control device according to claim 1, wherein the
heat radiation material is an adhesive that bonds the electronic
component to the housing.
4. The vehicle control device according to claim 1, wherein the
heat radiation material contains filler metal.
5. A vehicle control device comprising: a housing mounted on a
vehicle and made of metal; a substrate housed in the housing and
having a mounting surface that faces an inner surface of the
housing; an electronic component mounted on the mounting surface;
and a heat radiation material disposed in a second region, of a
first region and the second region between the electronic component
and the inner surface of the housing as seen in a direction that is
perpendicular to the mounting surface, wherein a dielectric
constant of a substance that is present in the first region is
lower than a dielectric constant of the heat radiation material,
the electronic component has a first circuit portion and a second
circuit portion; the first circuit portion radiates a larger amount
of noise than an amount of noise radiated from the second circuit
portion, and is superposed on the non-contact portion as seen in a
direction that is perpendicular to the mounting surface; and a
distance between the electronic component and the inner surface of
the housing in the direction that is perpendicular to the mounting
surface in the first region is longer than a distance between the
electronic component and the inner surface of the housing in the
direction which is perpendicular to the mounting surface in the
second region.
6. The vehicle control device according to claim 5, wherein the
inner surface of the housing has a recessed portion disposed in a
portion facing the first region and recessed in a direction away
from the electronic component.
7. The vehicle control device according to claim 5, wherein the
substance which is present in the first region is air.
8. The vehicle control device according to claim 5, wherein the
substance which is present in the first region is a heat radiation
material that is different from the heat radiation material and
that has a dielectric constant that is lower than that of the heat
radiation material and a thermal conductivity that is lower than
that of the heat radiation material.
9. The vehicle control device according to claim 5, wherein the
electronic component has a first circuit portion disposed so as to
be partially or wholly superposed on the first region and a second
circuit portion disposed so as to be wholly superposed on the
second region, as seen in the direction which is perpendicular to
the mounting surface.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a National Stage of International Application
No. PCT/JP2016/078260 filed Sep. 26, 2016, claiming priority based
on Japanese Patent Application No. 2015-186640 filed Sep. 24, 2015,
the contents of all of which are incorporated herein by reference
in their entirety.
TECHNICAL FIELD
This technique relates to a vehicle control device mounted on a
vehicle.
BACKGROUND ART
Measures against heat are required for electronic components that
control an in-vehicle apparatus mounted on a vehicle, a different
electronic component disposed in the same housing, and so forth in
order to avoid a reduction in performance due to a temperature
rise. A method of radiating heat generated by an electronic
component via a substrate on which the electronic component is
mounted is generally known as the measures against heat for the
electronic components. In the case where the amount of heat
radiated from the electronic component is large, however, the size
of the substrate must be increased in order to improve the heat
radiation performance.
Thus, Patent Document 1 proposes a technique of radiating heat
generated by an electronic component to a housing made of metal by
bringing the electronic component into contact with the housing via
an adhesive in order to reduce the size of the substrate while
enhancing the heat radiation performance for the electronic
component.
RELATED-ART DOCUMENTS
Patent Documents
Patent Document 1: Japanese Patent Application Publication No.
2004-228162 (JP 2004-228162 A)
SUMMARY
Problem to be Solved by the Invention
However, electromagnetic noise is radiated from an electronic
component during operation of the electronic component. Therefore,
if an electronic component is bonded to a housing made of metal
using an adhesive as in the related art, electromagnetic noise
radiated from the electronic component is propagated to the housing
via the adhesive, and the noise is easily propagated to an
in-vehicle device mounted on a vehicle via the housing. In
particular, the adhesive has a higher dielectric constant (relative
dielectric constant) than that of air, and the electromagnetic
noise which is radiated from the electronic component is easily
propagated to the housing via the adhesive. If the adhesive is not
used, on the other hand, propagation of the electromagnetic noise
to the housing is reduced, but the heat radiation performance for
the electronic component is impaired. Such a problem may be caused
also in the case where a heat radiation material (such as grease,
for example) other than the adhesive is used.
It is therefore an object to reduce propagation of electromagnetic
noise radiated from an electronic component to a housing while
securing the heat radiation performance for the electronic
component.
Means for Solving the Problem
An aspect provides a vehicle control device including:
a housing mounted on a vehicle and made of metal;
a substrate housed in the housing and having a mounting surface
that faces an inner surface of the housing;
an electronic component mounted on the mounting surface; and
a heat radiation material disposed between the electronic component
and the inner surface of the housing, in which:
the electronic component has a contact portion that contacts the
heat radiation material and a non-contact portion that does not
contact the heat radiation material, the contact portion and the
non-contact portion being portions of the electronic component on a
side facing the inner surface of the housing.
Another aspect provides a vehicle control device including:
a housing mounted on a vehicle and made of metal;
a substrate housed in the housing and having a mounting surface
that faces an inner surface of the housing;
an electronic component mounted on the mounting surface; and
a heat radiation material disposed in a second region, of a first
region and the second region between the electronic component and
the inner surface of the housing as seen in a direction that is
perpendicular to the mounting surface, in which
a dielectric constant of a substance that is present in the first
region is lower than a dielectric constant of the heat radiation
material.
Still another aspect provides a vehicle control device
including:
a housing mounted on a vehicle and made of metal;
a substrate housed in the housing and having a mounting surface
that faces an inner surface of the housing;
an electronic component mounted on the mounting surface; and
a heat radiation material disposed between the electronic component
and the inner surface of the housing, in which:
the electronic component has a first portion and a second portion
on a side facing the inner surface of the housing; and
a distance between the first portion and the inner surface of the
housing in a direction that is perpendicular to the mounting
surface is longer than a distance between the second portion and
the inner surface of the housing in the direction which is
perpendicular to the mounting surface.
Effects of the Invention
With the present vehicle control device, it is possible to reduce
propagation of electromagnetic noise radiated from an electronic
component to a housing while securing the heat radiation
performance for the electronic component.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a plan view of a vehicle control device according to a
first embodiment.
FIG. 1B is a sectional view of the vehicle control device taken
along the line IB-IB of FIG. 1A.
FIG. 2 is an enlarged sectional view of a part of the vehicle
control device according to the first embodiment.
FIG. 3A is a plan view of a printed circuit board of the vehicle
control device according to the first embodiment.
FIG. 3B is a plan view of a housing of the vehicle control device
according to the first embodiment.
FIG. 4 is an enlarged sectional view of a part of a vehicle control
device according to a second embodiment.
FIG. 5 is an enlarged sectional view of a part of a vehicle control
device according to a third embodiment.
PREFERRED EMBODIMENTS
First Embodiment
A vehicle control device according to a first embodiment will be
described below. FIG. 1A is a plan view of the vehicle control
device according to the first embodiment. FIG. 1B is a sectional
view of the vehicle control device taken along the line IB-IB of
FIG. 1A. FIG. 2 is an enlarged sectional view of a part of the
vehicle control device according to the first embodiment
illustrated in FIG. 1B. FIG. 3A is a plan view of a printed circuit
board of the vehicle control device according to the first
embodiment. FIG. 3B is a plan view of a housing of the vehicle
control device according to the first embodiment.
A vehicle control device 100 illustrated in FIGS. 1A and 1B is
mounted on a vehicle. The vehicle control device 100 is an ECU
(Electronic Control Unit), for example. The vehicle control device
100 includes a housing 200 mounted on the vehicle and made of
metal, e.g. aluminum, and a printed circuit board 300 housed in the
housing 200.
The printed circuit board 300 has a substrate 400 which is a
printed wiring board, and electronic components 501 and 502 mounted
on the substrate 400. The electronic components 501 and 502
generate heat during operation.
The substrate 400 has a pair of mounting surfaces 401 and 402. The
substrate 400 is a two-layer printed wiring board. The mounting
surfaces 401 and 402 each serve as a conductor layer on which a
conductor pattern is mainly disposed. As illustrated in FIG. 2, an
insulator layer (dielectric layer) 403 is disposed between the
mounting surfaces 401 and 402. The insulator layer 403 is a layer
on which an insulator is mainly disposed. The mounting surfaces 401
and 402 are provided with a solder resist (not illustrated) that
covers the conductor.
Here, a direction that is parallel to the mounting surface 401 of
the substrate 400 is defined as the X direction, a direction that
is orthogonal to the X direction and that is parallel to the
mounting surface 401 of the substrate 400 is defined as the Y
direction, and a direction that is perpendicular to the mounting
surface 401 of the substrate 400 is defined as the Z direction.
The electronic components 501 and 502 are mounted on one of the
mounting surfaces 401 and 402, namely the mounting surface 401.
An opening portion is formed in the housing 200 is formed with a,
and the opening portion is blocked by a lid body (not illustrated),
so that a housing space is formed. The printed circuit board 300 is
disposed in the housing space of the housing 200. The substrate 400
is housed in the housing 200 such that the mounting surface 401
faces an inner surface 201 of the housing 200. In the first
embodiment, the inner surface 201 of the housing 200 corresponds to
the bottom surface of the housing 200.
As illustrated in FIG. 1B, an adhesive 601, which is a heat
radiation material that conducts heat generated by the electronic
component 501 to the housing 200, is disposed between the
electronic component 501 and the inner surface 201 of the housing
200. An adhesive 602, which is a heat radiation material that
conducts heat generated by the electronic component 502 to the
housing 200, is disposed between the electronic component 502 and
the mounting surface 401 of the substrate 400. That is, the
electronic component 501 is bonded and fixed to the housing 200 by
the adhesive 601, and the electronic component 502 is bonded and
fixed to the housing 200 by the adhesive 602. In this way, the
adhesives 601 and 602 also fix the electronic components 501 and
502 (that is, the printed circuit board 300) to the housing 200, in
addition to radiating heat from the electronic components 501 and
502 to the housing 200.
The adhesives 601 and 602 contain a resin material as a base
material and filler metal to enhance the thermal conductivity of
the adhesives 601 and 602. This enhances the performance of heat
radiation of the electronic components 501 and 502 to the housing
200. The housing 200 may be cooled through natural convection, or
may be cooled by a cooling fan or the like.
The electronic component 501 is a semiconductor integrated circuit
constituted of a semiconductor package, and is a microcomputer, for
example. In the first embodiment, the electronic component 501 is a
semiconductor package of a QFP (Quad Flat Package) type with a heat
radiation plate.
As illustrated in FIG. 2, the electronic component 501 has a
semiconductor chip 511, a die pad 512 that supports the
semiconductor chip 511, a plurality of lead frames 513 that serve
as terminals to be joined to the substrate 400 by a joint member
701 such as solder, a plurality of bonding wires 514 that connect
the semiconductor chip 511 and the plurality of lead frames 513 to
each other, and a sealing resin 515 that seals such components.
In the first embodiment, a surface 512B of the die pad 512 that is
remote from a support surface 512A and supports the semiconductor
chip 511 is exposed from the sealing resin 515. That is, the die
pad 512 functions also as a heat radiation plate that radiates heat
generated by the semiconductor chip 511. The surface 512B of the
die pad 512 is joined to a land for heat radiation, that is, a
conductor pattern, formed on the mounting surface 401 of the
substrate 400 by a joint member 711 such as solder. Consequently, a
part of heat generated by the electronic component 501 is radiated
to the substrate 400.
The type of the semiconductor package which constitutes the
electronic component 501 is not limited to the QFP, and may be any
other type of semiconductor packages such as QFN, for example. The
electronic component 501 has been described as having a heat
radiation plate. However, the electronic component 501 may not have
a heat radiation plate.
As illustrated in FIGS. 1A and 3A, the semiconductor chip 511 has a
clock output circuit 521, a power supply circuit 522, a logic
circuit 523, an analog circuit 524, and another circuit 525. The
circuit 525 includes a semiconductor element that performs on/off
operation in accordance with a switching signal. In FIG. 3A, a part
of the sealing resin 515 of the electronic component 501 is not
illustrated.
In the first embodiment, a lead frame 513A, of the plurality of
lead frames 513, and the clock output circuit 521 are connected to
each other by a bonding wire 514A. A lead frame 513B, of the
plurality of lead frames 513, and the power supply circuit 522 are
connected to each other by a bonding wire 514B. A lead frame 513C,
of the plurality of lead frames 513, and the logic circuit 523 are
connected to each other by a bonding wire 514C. A lead frame 513D,
of the plurality of lead frames 513, and the analog circuit 524 are
connected to each other by a bonding wire 514D. A lead frame 513E,
of the plurality of lead frames 513, and the circuit 525E are
connected to each other by a bonding wire 514E.
The lead frame 513A and the bonding wire 514A constitute wiring 561
that serves as a transmission path which is connected to the clock
output circuit 521 and through which a clock signal is transmitted.
The lead frame 513B and the bonding wire 514B constitute wiring 562
connected to the power supply circuit 522. The lead frame 513C and
the bonding wire 514C constitute wiring 563 connected to the logic
circuit 523. The lead frame 513D and the bonding wire 514D
constitute wiring 564 connected to the analog circuit 524. The lead
frame 513E and the bonding wire 514E constitute wiring 565
connected to the circuit 525.
The clock output circuit 521 outputs a clock signal to another
circuit, e.g. the logic circuit 523, in the electronic component
501, or outputs a clock signal to another electronic component,
e.g. the electronic component 502, mounted on the substrate 400
through the wiring 561. The logic circuit 523 is a circuit that
operates in accordance with the clock signal.
Of the circuits 521 to 525, the clock output circuit 521 operates
to generate the most electromagnetic noise in a predetermined
frequency band, specifically a frequency band of 76 to 90 [MHz]
which is an FM broadcast frequency band. The clock output circuit
521 generates electromagnetic noise at a level exceeding a
threshold in the predetermined frequency band. Electromagnetic
noise is generated also from the wiring 561 which is connected to
the clock output circuit 521. A circuit portion 551, which serves
as the first circuit portion, is constituted to include the clock
output circuit 521 and the wiring 561.
Electromagnetic noise at a level exceeding a threshold in the
predetermined frequency band, e.g. a frequency band of 76 to 90
[MHz] which is an FM broadcast frequency band, is generated also
from the logic circuit 523 and the circuit 525. Electromagnetic
noise is generated also from the wiring 563 which is connected to
the logic circuit 523 and the wiring 565 which is connected to the
circuit 525. In the first embodiment, a circuit portion 553, which
serves as the first circuit portion, is constituted to include the
logic circuit 523 and the wiring 563. A circuit portion 555, which
serves as the first circuit portion, is constituted to include the
circuit 525 and the wiring 565.
A circuit portion 552 which serves as the second circuit portion is
constituted from the power supply circuit 522 and the wiring 562,
and a circuit portion 554 which serves as the second circuit
portion is constituted from the analog circuit 524 and the wiring
564.
That is, the circuit portions 551, 553, and 555 are noise radiation
sources that radiate a larger amount of noise in the predetermined
frequency band than the amount of noise radiated from the circuit
portions 552 and 554. In particular, the clock output circuit 521
is a circuit that cyclically performs switching operation, that is,
a circuit that cyclically repeatedly turns on and off, and cyclic
noise is radiated as electromagnetic noise from the clock output
circuit 521 and the wiring 561. Here, the term "cyclic" may mean
either "regular cycles" or "irregular cycles". In the first
embodiment, the term "cyclic" means "regular cycles". Noise
radiated from the circuit portions 551, 553, and 554, which each
serve as the first circuit portion, contains an integer times (n-th
harmonic wave) the frequency at which the circuit repeatedly turns
on and off.
In the description, electromagnetic noise radiated from the circuit
portions 551, 553, and 555, which each serve as the first circuit
portion, is larger in amount than electromagnetic noise radiated
from the circuit portions 552 and 554, which each serve as the
second circuit portion, in a frequency band of 76 to 90 [MHz] which
is an FM broadcast frequency band. However, such a frequency band
is not limiting. That is, the amount of noise radiated from the
first circuit portion may be larger than the amount of noise
radiated from the second circuit portion, that is, the amount of
noise radiated from the first circuit portion may exceed a
threshold, in a predetermined frequency band other than the FM
broadcast frequency band. Specific examples of the frequency band
include a frequency band of 0.5265 to 1.6065 [MHz], a frequency
band of 5.9 to 6.2 [MHz], a frequency band 30 of 54 to [MHz], a
frequency band of 76 to 90 [MHz], a frequency band of 142 to 170
[MHz], a frequency band of 335 to 470 [MHz], and a frequency band
of 770 to 960 [MHz]. The predetermined frequency band in which the
amount of noise from the first circuit portion is larger may be one
or a plurality of such frequency bands. The frequency bands
described above are merely a list of examples, and the
predetermined frequency band in which the amount of noise radiated
from the first circuit portion is larger is not limited to one of
the listed frequency bands or a combination of frequency bands from
the list. That is, the predetermined frequency band may be a
frequency band with a different range from the frequency bands
listed above. The amount of noise radiated from the first circuit
portion may be larger than the amount of noise radiated from the
second circuit portion over all frequencies, rather than in the
specific frequency band.
The adhesive 601 has a higher dielectric constant (relative
dielectric constant) than that of air. In the first embodiment, in
particular, the adhesive 601 contains filler metal, and thus has a
higher dielectric constant than that of an adhesive that does not
contain filler metal.
As illustrated in FIG. 2, the electronic component 501 has a
non-contact portion 531 that does not contact the adhesive 601 and
a contact portion 532 that contacts the adhesive 601. The
non-contact portion 531 and the contact portion 532 are surface
portions of the electronic component 501 on the side facing the
inner surface 201 of the housing 200. When seen in the Z direction,
a region R1 which serves as the first region is present between the
non-contact portion 531 and the inner surface 201, and a region R2
which serves as the second region is present between the contact
portion 532 and the inner surface 201. That is, the adhesive 601 is
not present in the region R1, and the adhesive 601 is disposed in
the region R2.
When the vehicle control device 100 is seen in the Z direction, the
circuit portions 551, 553, and 555, which are each a noise
radiation source, are superposed on the non-contact portion 531,
that is, the region R1. Specifically, the circuit portions 551,
553, and 555 are partially or wholly superposed on the non-contact
portion 531 (region R1). In the first embodiment, as seen in the Z
direction, the circuit portion 551 is wholly, and the circuit
portions 553 and 555 are partially, superposed on the non-contact
portion 531 (region R1) (FIG. 1A). In other words, a projection
region obtained by projecting the circuit portions 551, 553, and
555 in the Z direction onto the XY plane which is parallel to the
mounting surface 401 of the substrate 400 and a projection region
obtained by projecting the non-contact portion 531 in the Z
direction onto the XY plane are superposed on each other.
When the vehicle control device 100 is seen in the Z direction, the
circuit portion 552 which has the power supply circuit 522 and the
circuit portion 554 which has the analog circuit 524 are wholly
superposed on the contact portion 532, that is, the region R2. In
other words, a projection region obtained by projecting the circuit
portions 552 and 554 in the Z direction onto the XY plane which is
parallel to the mounting surface 401 of the substrate 400 and a
projection region obtained by projecting the contact portion 532 in
the Z direction onto the XY plane are superposed on each other.
When the vehicle control device 100 is seen in the Z direction, the
circuit portion 553 which has the logic circuit 523 and the circuit
portion 555 which has the circuit 525 are partially superposed on
the contact portion 532.
As illustrated in FIGS. 1B and 2, the region R1 between the
non-contact portion 531 and the inner surface 201 of the housing
200 does not have the adhesive 601, and is a void. That is, a
substance that is present in the region R1 is air. The dielectric
constant (relative dielectric constant) of air is lower than the
dielectric constant (relative dielectric constant) of the adhesive
601, and therefore the parasitic capacitance between the circuit
portions 551, 553, and 555 and the housing 200 is reduced, which
reduces propagation of electromagnetic noise radiated from the
circuit portions 551, 553, and 555 to the housing 200. In
particular, the circuit portion 551, which generates the most
electromagnetic noise, is wholly superposed on the region R1, and
therefore propagation of electromagnetic noise generated by the
circuit portion 551 to the housing 200 can be reduced effectively.
Consequently, propagation of noise from the housing 200 to
electronic apparatuses etc. mounted on the vehicle can be reduced.
Hence, the vehicle control device 100 can meet the international
standard CISPR 25, for example.
The adhesive 601 has a higher thermal conductivity than that of
air. Heat generated by the electronic component 501 is conducted to
the housing 200 via the adhesive 601 which is provided between the
contact portion 532 of the electronic component 501 and the housing
200, and thus the heat radiation performance for the electronic
component 501 can be secured.
In the first embodiment, as illustrated in FIGS. 1B and 3B,
projecting portions 211 and 212 that project in the +Z direction
toward the electronic components 501 and 502 are formed on the
inner surface 201 of the housing 200 at positions facing the
electronic components 501 and 502, respectively.
The projecting portion 211 serves as a pedestal for the electronic
component 501, and the projecting portion 212 serves as a pedestal
for the electronic component 502. A recessed portion 211B recessed
in the -Z direction away from the electronic component 501 is
formed in a facing surface (distal end surface) 211A of the
projecting portion 211, which faces the electronic component 501,
at a position facing the non-contact portion 531. The electronic
component 501 is bonded to the facing surface 211A of the
projecting portion 211 using the adhesive 601. The electronic
component 502 is bonded to a facing surface 212A of the projecting
portion 212, which faces the electronic component 502, using the
adhesive 602.
In the first embodiment, when seen in the Z direction, as
illustrated in FIG. 1A, the non-contact portion 531 which is not
contacted by the adhesive 601 is superposed on the recessed portion
211B. In other words, a projection region obtained by projecting
the non-contact portion 531 in the Z direction onto the XY plane is
superposed on a projection region obtained by projecting the
recessed portion 211B in the Z direction onto the XY plane. Hence,
a distance L1 (FIG. 2) in the Z direction between the non-contact
portion 531 and the inner surface 201 of the housing 200 in the
region R1 is longer than a distance L2 (FIG. 2) in the Z direction
between the contact portion 532 and the inner surface 201 of the
housing 200 in the region R2.
Consequently, the circuit portions 551, 553, and 555 which are
noise radiation sources of the electronic component 501,
particularly the circuit portion 551, are located away from the
housing 200. Thus, the parasitic capacitance between the circuit
portions 551, 553, and 555 and the housing 200 is reduced, which
reduces propagation of electromagnetic noise radiated from the
circuit portions 551, 553, and 555 to the housing 200. Hence,
propagation of noise from the housing 200 to electronic apparatuses
etc. mounted on the vehicle can be reduced.
Second Embodiment
A vehicle control device according to a second embodiment will be
described. FIG. 4 is an enlarged sectional view of a part of the
vehicle control device according to the second embodiment.
Components of a vehicle control device 100A according to the second
embodiment that are similar to those of the vehicle control device
100 according to the first embodiment are given the same reference
numerals to omit description. In the vehicle control device 100A
according to the second embodiment, the application amount of the
adhesive 601 is different from that in the first embodiment. That
is, in the second embodiment, the adhesive 601 protrudes into the
recessed portion 211B. That is, the recessed portion 211B acts also
as a clearance portion for the adhesive 601 which has been applied
excessively.
The electronic component 501 has a surface portion 541, which
serves as the first portion, and a surface portion 542, which
serves as the second portion, other than the surface portion 541.
The surface portions 541 and 542 are surface portions of the
electronic component 501 on the side facing the inner surface 201
of the housing 200. The electronic component 501 has the circuit
portion 551 which is disposed so as to be superposed on the surface
portion 541 as seen in the Z direction, and the circuit portion 554
which is disposed so as to be superposed on the surface portion
542. As described in relation to the first embodiment, the circuit
portion 551 radiates a larger amount of noise in the predetermined
frequency band, e.g. a frequency band of 76 to 90 [MHz] which is an
FM broadcast frequency band, than the amount of noise radiated from
the circuit portion 554. The circuit portion 551 is disposed so as
to be partially or wholly, and wholly in the second embodiment,
superposed on the surface portion 541 as seen in the Z direction.
The circuit portion 554 is wholly superposed on the surface portion
542 as seen in the Z direction.
As in the first embodiment, the projecting portion 211 which
projects in the +Z direction is formed on the inner surface 201.
The recessed portion 211B which is recessed in the -Z direction
away from the electronic component 501 is formed in the facing
surface 211A of the projecting portion 211 at a position facing the
surface portion 541 of the electronic component 501. That is, the
surface portion 541 of the electronic component 501 faces the
recessed portion 211B in the Z direction, and the surface portion
542 of the electronic component 501 faces the facing surface 211A
(excluding the recessed portion 211B) in the Z direction. Thus, a
distance L11 in the Z direction between the surface portion 541 of
the electronic component 501 and the inner surface 201 of the
housing 200 is longer than a distance L12 in the Z direction
between the surface portion 542 of the electronic component 501 and
the inner surface 201 of the housing 200.
With the second embodiment, the circuit portion 551 of the
electronic component 501 is located away from the housing 200 since
the distance L11 is longer than the distance L12, even if the
adhesive 601 is provided between the surface portion 541 of the
electronic component 501 and the inner surface 201 of the housing
200, and the parasitic capacitance between the circuit portion 551
and the housing 200 is reduced, which reduces propagation of
electromagnetic noise radiated from the circuit portion 551 to the
housing 200. Consequently, propagation of noise from the housing
200 to electronic apparatuses etc. mounted on the vehicle can be
reduced. Hence, the vehicle control device 100A can meet the
international standard CISPR 25, for example.
Heat generated by the electronic component 501 is conducted to the
housing 200 via the adhesive 601 which is provided between the
electronic component 501 and the housing 200, and thus the heat
radiation performance for the electronic component 501 can be
secured.
An extra amount of the adhesive 601 applied flows to the recessed
portion 211B, and therefore the amount of the adhesive 601 which
contacts the surface portion 541 is reduced, which reduces the
parasitic capacitance between the circuit portion 551 and the
housing 200.
Third Embodiment
A vehicle control device according to a third embodiment will be
described. FIG. 5 is an enlarged sectional view of a part of the
vehicle control device according to the third embodiment.
Components of a vehicle control device 100B according to the third
embodiment that are similar to those of the vehicle control device
100 according to the first embodiment and the vehicle control
device 100A according to the second embodiment are given the same
reference numerals to omit description. In the first embodiment,
the recessed portion 211B is formed in the facing surface 211A of
the projecting portion 211 at a position facing the non-contact
portion 531. In the third embodiment, the recessed portion 211B is
not formed in the facing surface 211A, and the distance L1 between
the non-contact portion 531 and the inner surface 201 (facing
surface 211A) of the housing 200 in the region R1 is equal to the
distance L2 between the contact portion 532 and the inner surface
201 (facing surface 211A) of the housing 200 in the region R2.
While the electronic component 501 is bonded to the projecting
portion 211, the electronic component 501 may be bonded to a
location other than the projecting portion 211.
In FIG. 5, when the vehicle control device 100B is seen in the Z
direction, the circuit portion 551, which is a noise radiation
source, is superposed on the non-contact portion 531. Specifically,
the circuit portion 551 is partially or wholly, and wholly in the
third embodiment, superposed on the non-contact portion 531 as seen
in the Z direction. In other words, a projection region obtained by
projecting the circuit portion 551 in the Z direction onto the XY
plane which is parallel to the mounting surface 401 of the
substrate 400 and a projection region obtained by projecting the
non-contact portion 531 in the Z direction onto the XY plane are
superposed on each other. The circuit portion 554 is wholly
superposed on the contact portion 532 as seen in the Z
direction.
The region R1 between the non-contact portion 531 and the housing
200 does not have the adhesive 601, and is a void. Air has a lower
dielectric constant (relative dielectric constant) than the
dielectric constant (relative dielectric constant) of the adhesive
601. Therefore, the parasitic capacitance between the circuit
portion 551 and the housing 200 is reduced. Thus, propagation of
electromagnetic noise radiated from the circuit portion 551 to the
housing 200 can be reduced even if the distance L1 is equal to the
distance L2. Consequently, propagation of noise from the housing
200 to electronic apparatuses etc. mounted on the vehicle can be
reduced. Hence, the vehicle control device 100B can meet the
international standard CISPR 25, for example.
Heat generated by the electronic component 501 is conducted to the
housing 200 via the adhesive 601 which is provided between the
contact portion 532 of the electronic component 501 and the housing
200, and thus the heat radiation performance for the electronic
component 501 can be secured.
SUMMARY OF EMBODIMENTS
An embodiment provides a vehicle control device (100, 100B)
including:
a housing (200) mounted on a vehicle and made of metal;
a substrate (400) housed in the housing (200) and having a mounting
surface (401) that faces an inner surface (201) of the housing
(200);
an electronic component (501) mounted on the mounting surface
(401); and
a heat radiation material (601) disposed between the electronic
component (501) and the inner surface (201) of the housing (200),
in which:
the electronic component (501) has a contact portion (532) that
contacts the heat radiation material (601) and a non-contact
portion (531) that does not contact the heat radiation material
(601), the contact portion (532) and the non-contact portion (531)
being portions of the electronic component (501) on a side facing
the inner surface (201) of the housing (200).
Consequently, it is possible to reduce propagation of
electromagnetic noise radiated from the electronic component (501)
to the housing (200) while securing the heat radiation performance
for the electronic component (501).
In the vehicle control device (100, 100B) according to the
embodiment,
the electronic component (501) has a first circuit portion (551,
553, 555) and a second circuit portion (552, 554); and
the first circuit portion (551, 553, 555) radiates a larger amount
of noise than an amount of noise radiated from the second circuit
portion (552, 554), and is superposed on the non-contact portion
(531) as seen in a direction (Z direction) that is perpendicular to
the mounting surface (401).
Consequently, it is possible to effectively reduce conduction of
electromagnetic noise radiated from the first circuit portion (551,
553, 555) to the housing (200).
In the vehicle control device (100) according to the embodiment, a
distance (L1) between the non-contact portion (531) and the inner
surface (201) of the housing (200) in the perpendicular direction
(Z direction) is longer than a distance (L2) between the contact
portion (532) and the inner surface (201) of the housing (200) in
the direction (Z direction) which is perpendicular to the mounting
surface (401).
Consequently, it is possible to reduce propagation of
electromagnetic noise radiated from the electronic component (501)
to the housing (200) while securing the heat radiation performance
for the electronic component (501).
In the vehicle control device (100) according to the embodiment,
the inner surface (201) of the housing (200) has a recessed portion
(211B) disposed at a position facing the non-contact portion (531)
and recessed in a direction away from the electronic component
(50).
Consequently, heat generated by the electronic component (501) is
conducted to the inner surface (211) of the housing (200), which
secures the heat radiation performance for the electronic component
(501), and conduction of electromagnetic noise radiated from the
electronic component (501) to the housing (200) can be effectively
reduced by the recessed portion (211B).
An embodiment provides a vehicle control device (100, 100B)
including:
a housing (200) mounted on a vehicle and made of metal;
a substrate (400) housed in the housing (200) and having a mounting
surface (401) that faces an inner surface (201) of the housing
(200);
an electronic component (501) mounted on the mounting surface
(401); and
a heat radiation material (601) disposed in a second region (R2),
of a first region (R1) and the second region (R2) between the
electronic component (501) and the inner surface (201) of the
housing (200) as seen in a direction (Z direction) that is
perpendicular to the mounting surface (401), in which
a dielectric constant of a substance that is present in the first
region (R1) is lower than a dielectric constant of the heat
radiation material (601).
Consequently, it is possible to reduce propagation of
electromagnetic noise radiated from the electronic component (501)
to the housing (200) while securing the heat radiation performance
for the electronic component (501).
In the vehicle control device (100) according to the embodiment, a
distance (L1) between the electronic component (501) and the inner
surface (201) of the housing (200) in the direction (Z direction)
that is perpendicular to the mounting surface (401) in the first
region (R1) is longer than a distance (L2) between the electronic
component (501) and the inner surface (201) of the housing (200) in
the direction (Z direction) which is perpendicular to the mounting
surface (401) in the second region (R2).
Consequently, it is possible to further effectively reduce
propagation of electromagnetic noise radiated from the electronic
component (501) to the housing (200).
In the vehicle control device (100) according to the embodiment,
the inner surface (201) of the housing (200) has a recessed portion
(211B) disposed in a portion facing the first region (R1) and
recessed in a direction (-Z direction) away from the electronic
component (501).
Consequently, heat generated by the electronic component (501) is
conducted to the inner surface (211), which secures the heat
radiation performance for the electronic component (501), and
conduction of electromagnetic noise radiated from the electronic
component (501) to the housing (200) can be effectively reduced by
the recessed portion (211B).
In the vehicle control device (100B) according to the embodiment, a
distance (L1) between the electronic component (501) and the inner
surface (201) of the housing (200) in the direction (Z direction)
which is perpendicular to the mounting surface (401) in the first
region (R1) is equal to a distance (L2) between the electronic
component (501) and the inner surface (201) of the housing (200) in
the direction (Z direction) which is perpendicular to the mounting
surface (401) in the second region (R2).
Consequently, it is possible to effectively reduce propagation of
electromagnetic noise radiated from the electronic component (501)
to the housing (200).
In the vehicle control device (100, 100B) according to the
embodiment, the substance which is present in the first region (R1)
is air.
Consequently, it is possible to effectively reduce propagation of
electromagnetic noise radiated from the electronic component (501)
to the housing (200).
In the vehicle control device (100, 100B) according to the
embodiment, the substance which is present in the first region (R1)
is a heat radiation material that is different from the heat
radiation material (601) and that has a dielectric constant that is
lower than that of the heat radiation material (601) and a thermal
conductivity that is lower than that of the heat radiation material
(601).
Consequently, it is possible to effectively reduce propagation of
electromagnetic noise radiated from the electronic component (501)
to the housing (200).
An embodiment provides a vehicle control device (100A)
including:
a housing (200) mounted on a vehicle and made of metal;
a substrate (400) housed in the housing (200) and having a mounting
surface (401) that faces an inner surface (201) of the housing
(200);
an electronic component (501) mounted on the mounting surface
(401); and
a heat radiation material (601) disposed between the electronic
component (501) and the inner surface (201) of the housing (200),
in which:
the electronic component (501) has a first portion (541) and a
second portion (542) on a side facing the inner surface (201) of
the housing (200); and
a distance (L11) between the first portion (541) and the inner
surface (201) of the housing (200) in a direction (Z direction)
that is perpendicular to the mounting surface (401) is longer than
a distance (L12) between the second portion (542) and the inner
surface (201) of the housing (200) in the direction (Z direction)
which is perpendicular to the mounting surface (401).
Consequently, it is possible to reduce propagation of
electromagnetic noise radiated from the electronic component (501)
to the housing (200) while securing the heat radiation performance
for the electronic component (501).
In the vehicle control device (100A) according to the embodiment,
the inner surface (201) of the housing (200) has a recessed portion
(211B) disposed at a position facing the first portion (541) and
recessed in a direction (-Z direction) away from the electronic
component (501).
Consequently, heat generated by the electronic component (501) is
conducted to the inner surface (211) of the housing (200), which
secures the heat radiation performance for the electronic component
(501), and conduction of electromagnetic noise radiated from the
electronic component (501) to the housing (200) can be effectively
reduced by the recessed portion (211B).
In the vehicle control device (100, 100B) according to the
embodiment, the electronic component (501) has a first circuit
portion (551, 553, 555) disposed so as to be partially or wholly
superposed on the first region (R1) and a second circuit portion
(552, 554) disposed so as to be wholly superposed on the second
region (R2), as seen in the direction (Z direction) which is
perpendicular to the mounting surface (401).
Consequently, it is possible to effectively reduce conduction of
electromagnetic noise radiated from the first circuit portion (551,
553, 555) to the housing (200).
In the vehicle control device (100A) according to the embodiment,
the electronic component (501) has a first circuit portion (551)
disposed so as to be partially or wholly superposed on the first
portion (541) and a second circuit portion (554) disposed so as to
be wholly superposed on the second portion (542), as seen in the
direction (Z direction) which is perpendicular to the mounting
surface (401).
Consequently, it is possible to effectively reduce conduction of
electromagnetic noise radiated from the first circuit portion (551)
to the housing (200).
In the vehicle control device (100, 100A, 100B) according to the
embodiment, the first circuit portion (551, 553, 555) radiates a
larger amount of noise in a predetermined frequency band than an
amount of noise radiated from the second circuit portion (552,
554).
Consequently, it is possible to effectively reduce conduction of
electromagnetic noise radiated from the first circuit portion (551,
553, 555), which radiates a large amount noise, to the housing
(200).
In the vehicle control device (100, 100A, 100B) according to the
embodiment, the first circuit portion (551, 553, 555) includes a
circuit (521, 523, 525) that cyclically performs switching
operation.
Consequently, it is possible to effectively reduce conduction of
electromagnetic noise radiated from the circuit (521, 523, 525) of
the first circuit portion (551, 553, 555), which radiates noise
that peaks at a specific frequency, to the housing (200).
In the vehicle control device (100, 100A, 100B) according to the
embodiment, the first circuit portion (551, 553, 555) includes
wiring (561, 563, 565) connected to a circuit that cyclically
performs switching operation.
Consequently, it is possible to effectively reduce conduction of
electromagnetic noise radiated from the wiring (561, 563, 565) for
the first circuit portion (551, 553, 555), which radiates noise
that peaks at a specific frequency, to the housing (200).
In the vehicle control device (100, 100A, 100B) according to the
embodiment, the circuit which cyclically performs switching
operation is a clock output circuit (521) that outputs a clock
signal, a circuit (523) that operates in accordance with a clock
signal, or a circuit (525) that includes a semiconductor element
that performs on/off operation in accordance with a switching
signal.
Consequently, it is possible to effectively reduce conduction of
electromagnetic noise due to operation of the clock output circuit
(521), the circuit (523), or the semiconductor element (525) to the
housing (200).
In the vehicle control device (100, 100A, 100B) according to the
embodiment, the heat radiation material is an adhesive (601) that
bonds the electronic component (501) to the housing (200).
Consequently, heat generated by the electronic component (501) can
be conducted to the housing (200) via the adhesive (601) while
fixing the electronic component (501) to the housing 200 using the
adhesive (601).
In the vehicle control device (100, 100A, 100B) according to the
embodiment, the heat radiation material (601) contains filler
metal.
Consequently, the thermal conductivity of the heat radiation
material is enhanced, and the heat radiation performance for the
electronic component (501) is improved.
Possibility of Other Embodiments
In the first to third embodiments described above, the electronic
component 501 is a microcomputer of an ECU. However, the present
invention is not limited thereto. The electronic component 501 may
be any electronic component that controls an in-vehicle device
mounted on a vehicle, that controls a different electronic
component disposed in the housing 200, or the like. For example,
the electronic component 501 may be a driver IC that has a
semiconductor element such as a MOS-FET that repeatedly performs
on/off operation in the cycle of a PWM signal that serves as a
switching signal. In this case, the semiconductor element or wiring
for the semiconductor element serves as the first circuit portion
which is a noise radiation source.
Alternatively, the electronic component 501 may be a switching
power supply IC that has a clock output circuit or a circuit that
includes a semiconductor element that performs on/off operation in
accordance with a switching signal, for example. In this case, the
first circuit portion may be a circuit portion that has the clock
output circuit or wiring for the clock output circuit, or may be a
circuit portion that has the circuit which includes the
semiconductor element or wiring for the circuit.
In the first to third embodiments, the circuit portions 551, 553,
and 555 radiate much electromagnetic noise in a frequency band of
76 to 90 [MHz] which is an FM broadcast frequency band, and
therefore the predetermined frequency band in which noise
propagation is to be reduced is a frequency band of 76 to 90 [MHz].
However, such a frequency band is not limiting. That is, the amount
of noise radiated from the first circuit portion may be larger than
the amount of noise radiated from the second circuit portion, that
is, the amount of noise radiated from the first circuit portion may
exceed a threshold, in a predetermined frequency band other than
the FM broadcast frequency band. Specifically, the first to third
embodiments are suitable in the case where the predetermined
frequency band is any one of a frequency band of 0.5265 to 1.6065
[MHz], a frequency band of 5.9 to 6.2 [MHz], a frequency band 30 of
54 to [MHz], a frequency band of 76 to 90 [MHz], a frequency band
of 142 to 170 [MHz], a frequency band of 335 to 470 [MHz], and a
frequency band of 770 to 960 [MHz].
In the first to third embodiments, the heat radiation material is
the adhesive 601. However, the present invention is not limited
thereto. For example, the heat radiation material may be heat
radiation grease, a heat radiation sheet, etc. In the description,
the substance which is present in the region R1 is air which has a
lower dielectric constant than that of the heat radiation material.
However, the substance which is present in the region R1 is not
limited to air, and may be a substance other than air that has a
lower dielectric constant than that of the heat radiation
material.
In the first to third embodiments, the circuit portion 551 which is
a noise radiation source is the clock output circuit 521 and the
wiring 530. However, the present invention is not limited thereto,
and the circuit portion 551 may be the clock output circuit 521
alone or the wiring 561 alone. Similarly, the circuit portion 553
may be the circuit 523 alone or the wiring 563 alone, and the
circuit portion 555 may be the circuit 525 alone or the wiring 565
alone.
In the first to third embodiments, the substrate 400 is a two-layer
printed wiring board. However, the substrate 400 is not limited to
having two layers, and the substrate 400 may be a printed wiring
board with one layer or three or more layers.
In the first to third embodiments, the substance which is present
in the region R1 is air. However, the present invention is not
limited thereto. The substance which is present in the first region
R1 may be a heat radiation material of a different material that
has a lower dielectric constant than that of the adhesive 601 which
is present in the region R2 and a lower thermal conductivity than
that of the adhesive 601. For example, the substance which is
present in the first region R1 may be an adhesive of a different
material from that of the adhesive 601. That is, adhesives may be
present in both the region R1 and the region R2. In this case, it
is only necessary that the adhesive 601 in the region R2 should
have a higher thermal conductivity (heat radiation performance) and
a higher dielectric constant than those of the adhesive in the
region R1.
INDUSTRIAL APPLICABILITY
The present vehicle control device is suitably used when it is
requested to reduce propagation of electromagnetic noise radiated
from an electronic component to a housing while securing the heat
radiation performance for the electronic component.
DESCRIPTION OF THE REFERENCE NUMERALS
100 VEHICLE CONTROL DEVICE 200 HOUSING 201 INNER SURFACE 211b
RECESSED PORTION 400 SUBSTRATE 401 MOUNTING SURFACE 501 ELECTRONIC
COMPONENT 531 NON-CONTACT PORTION 532 CONTACT PORTION 541 SURFACE
PORTION (FIRST PORTION) 542 SURFACE PORTION (SECOND PORTION) 551,
553, 555 CIRCUIT PORTION (FIRST CIRCUIT PORTION) 552, 554 CIRCUIT
PORTION (SECOND CIRCUIT PORTION) 601 ADHESIVE (HEAT RADIATION
MATERIAL) R1 REGION (FIRST REGION) R2 REGION (SECOND REGION)
* * * * *